#include<bits/stdc++.h> using namespace std; int main(){ char a,b; cin>>a; b=int(a); if(b>=97&&b<=122){ b-=32; cout<<char(b); return 0; } if(b>=65&&b<=90){ b+=32; cout<<char(b); } return 0; }

难度适中，考察我们对ASCII码表的熟悉度 一般做过CP003118的都觉得简单~ 正解：

入门题解11，这题考的其实就是对ASCII的熟悉，首先，你判断大小写需要用到ASCII，然后，大小写转换需要用到ASCII。 以下是我的代码：

#include<iostream> using namespace std; int main(){ char a; cin >> a; if (a=='a')cout<<"A"; else if (a == 'b') cout << "B"; else if (a == 'c') cout << "C"; else if (a == 'd') cout << "D"; else if (a == 'e') cout << "E"; else if (a == 'f') cout << "F"; else if (a == 'g') cout << "G"; else if (a == 'h') cout << "H"; else if (a == 'i') cout << "I"; else if (a == 'j') cout << "J"; else if (a == 'k') cout << "K"; else if (a == 'l') cout << "L"; else if (a == 'n') cout << "N"; else if (a == 'm') cout << "M"; else if (a == 'o') cout << "O"; else if (a == 'p') cout << "P"; else if (a == 'q') cout << "Q"; else if (a == 'r') cout << "R"; else if (a == 's') cout << "S"; else if (a == 't') cout << "T"; else if (a == 'u') cout << "U"; else if (a == 'v') cout << "V"; else if (a == 'w') cout << "W"; else if (a == 'x') cout << "X"; else if (a == 'y') cout << "Y"; else if (a == 'z') cout << "Z"; else if (a == 'A') cout << "a"; else if (a == 'B') cout << "b"; else if (a == 'C') cout << "c"; else if (a == 'D') cout << "d"; else if (a == 'E') cout << "e"; else if (a == 'F') cout << "f"; else if (a == 'G') cout << "g"; else if (a == 'H') cout << "h"; else if (a == 'I') cout << "i"; else if (a == 'J') cout << "j"; else if (a == 'K') cout << "k"; else if (a == 'L') cout << "l"; else if (a == 'N') cout << "n"; else if (a == 'M') cout << "m"; else if (a == 'O') cout << "o"; else if (a == 'T') cout << "t"; else if (a == 'U') cout << "u"; else if (a == 'V') cout << "v"; else if (a == 'W') cout << "w"; else if (a == 'X') cout << "x"; else if (a == 'Y') cout << "y"; else if (a == 'Z') cout << "z"; return 0; }

#include<iostream> using namespace std; int main(){ char a; cin>>a; int b; b=a; if(a>='a'&&a<='z'){ b-=32; a=b; } else if(a>='A'&&a<='Z'){ b+=32; a=b; } cout<<a; return 0; }

#include<iostream> using namespace std; int main(){ char a; cin >> a; if (a == 'a') cout << "A"; else if (a == 'b') cout << "B"; else if (a == 'c') cout << "C"; else if (a == 'd') cout << "D"; else if (a == 'e') cout << "E"; else if (a == 'f') cout << "F"; else if (a == 'g') cout << "G"; else if (a == 'h') cout << "H"; else if (a == 'i') cout << "I"; else if (a == 'j') cout << "J"; else if (a == 'k') cout << "K"; else if (a == 'l') cout << "L"; else if (a == 'n') cout << "N"; else if (a == 'm') cout << "M"; else if (a == 'o') cout << "O"; else if (a == 'p') cout << "P"; else if (a == 'q') cout << "Q"; else if (a == 'r') cout << "R"; else if (a == 's') cout << "S"; else if (a == 't') cout << "T"; else if (a == 'u') cout << "U"; else if (a == 'v') cout << "V"; else if (a == 'w') cout << "W"; else if (a == 'x') cout << "X"; else if (a == 'y') cout << "Y"; else if (a == 'z') cout << "Z"; else if (a == 'A') cout << "a"; else if (a == 'B') cout << "b"; else if (a == 'C') cout << "c"; else if (a == 'D') cout << "d"; else if (a == 'E') cout << "e"; else if (a == 'F') cout << "f"; else if (a == 'G') cout << "g"; else if (a == 'H') cout << "h"; else if (a == 'I') cout << "i"; else if (a == 'J') cout << "j"; else if (a == 'K') cout << "k"; else if (a == 'L') cout << "l"; else if (a == 'N') cout << "n"; else if (a == 'M') cout << "m"; else if (a == 'O') cout << "o"; else if (a == 'T') cout << "t"; else if (a == 'U') cout << "u"; else if (a == 'V') cout << "v"; else if (a == 'W') cout << "w"; else if (a == 'X') cout << "x"; else if (a == 'Y') cout << "y"; else if (a == 'Z') cout << "z"; return 0; }

include<iostream> using namespace std; int main (){ char a; cin>>a; if(a>='a'&&a<='z'){ a=a-'a'+'A'; } else if(a>='A'&&a<='Z'){ a=a-'A'+'a'; } cout<<a; return 0; }

题解

#include <bits/stdc++.h> using namespace std; int main() { char n; cin>>n; if(n=='a') cout<<"A"; else if(n=='b') cout<<"B"; else if(n=='c') cout<<"C"; else if(n=='d') cout<<"D"; else if(n=='e') cout<<"E"; else if(n=='f') cout<<"F"; else if(n=='g') cout<<"G"; else if(n=='h') cout<<"H"; else if(n=='i') cout<<"I"; else if(n=='j') cout<<"J"; else if(n=='k') cout<<"K"; else if(n=='l') cout<<"L"; else if(n=='m') cout<<"M"; else if(n=='n') cout<<"N"; else if(n=='o') cout<<"O"; else if(n=='p') cout<<"P"; else if(n=='q') cout<<"Q"; else if(n=='r') cout<<"R"; else if(n=='s') cout<<"S"; else if(n=='t') cout<<"T"; else if(n=='u') cout<<"U"; else if(n=='v') cout<<"V"; else if(n=='w') cout<<"W"; else if(n=='x') cout<<"X"; else if(n=='y') cout<<"Y"; else if(n=='z') cout<<"Z"; if(n=='A') cout<<"a"; else if(n=='B') cout<<"b"; else if(n=='C') cout<<"c"; else if(n=='D') cout<<"d"; else if(n=='E') cout<<"e"; else if(n=='F') cout<<"f"; else if(n=='G') cout<<"g"; else if(n=='H') cout<<"h"; else if(n=='I') cout<<"i"; else if(n=='J') cout<<"j"; else if(n=='K') cout<<"k"; else if(n=='L') cout<<"l"; else if(n=='M') cout<<"m"; else if(n=='N') cout<<"n"; else if(n=='O') cout<<"o"; else if(n=='P') cout<<"p"; else if(n=='Q') cout<<"q"; else if(n=='R') cout<<"r"; else if(n=='S') cout<<"s"; else if(n=='T') cout<<"t"; else if(n=='U') cout<<"u"; else if(n=='V') cout<<"v"; else if(n=='W') cout<<"w"; else if(n=='X') cout<<"x"; else if(n=='Y') cout<<"y"; else if(n=='Z') cout<<"z"; return 0; }

#include <iostream> using namespace std; int main(){ char n; cin>>n; if(n=='a'){cout <<"A";} else if(n=='b'){cout <<"B";} else if(n=='c'){cout <<"C";} else if(n=='d'){cout <<"D";} else if(n=='e'){cout <<"E";} else if(n=='f'){cout <<"F";} else if(n=='g'){cout <<"G";} else if(n=='h'){cout <<"H";} else if(n=='i'){cout <<"I";} else if(n=='j'){cout <<"J";} else if(n=='k'){cout <<"K";} else if(n=='l'){cout <<"L";} else if(n=='m'){cout <<"M";} else if(n=='n'){cout <<"N";} else if(n=='o'){cout <<"O";} else if(n=='p'){cout <<"P";} else if(n=='q'){cout <<"Q";} else if(n=='r'){cout <<"R";} else if(n=='s'){cout <<"S";} else if(n=='t'){cout <<"T";} else if(n=='u'){cout <<"U";} else if(n=='v'){cout <<"V";} else if(n=='w'){cout <<"W";} else if(n=='x'){cout <<"X";} else if(n=='y'){cout <<"Y";} else if(n=='z'){cout <<"Z";} else if(n=='A'){cout <<"a";} else if(n=='B'){cout <<"b";} else if(n=='C'){cout <<"c";} else if(n=='D'){cout <<"d";} else if(n=='E'){cout <<"e";} else if(n=='F'){cout <<"f";} else if(n=='G'){cout <<"g";} else if(n=='H'){cout <<"h";} else if(n=='I'){cout <<"i";} else if(n=='J'){cout <<"j";} else if(n=='K'){cout <<"k";} else if(n=='L'){cout <<"l";} else if(n=='M'){cout <<"m";} else if(n=='N'){cout <<"n";} else if(n=='O'){cout <<"o";} else if(n=='P'){cout <<"p";} else if(n=='Q'){cout <<"q";} else if(n=='R'){cout <<"r";} else if(n=='S'){cout <<"s";} else if(n=='T'){cout <<"t";} else if(n=='U'){cout <<"u";} else if(n=='V'){cout <<"v";} else if(n=='W'){cout <<"w";} else if(n=='X'){cout <<"x";} else if(n=='Y'){cout <<"y";} else if(n=='Z'){cout <<"z";} return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ char x; cin>>x; if(x>='A'&&x<='Z'){ x=x+32; cout<<x; } else if(x>='a'&&x<='z'){ x=x-32; cout<<x; } }

#include<iostream> using namespace std; int main(){ char a,b; cin>>a; if(a<='Z'&&a>='A'){ b=a+32; cout<<b; } else{ b=a-32; cout<<b; } }

#include<bits/stdc++.h> using namespace std; int main(){ char n; cin>>n; if(n>='a' and n<='z'){ cout<<char(n-32); } else{ cout<<char(n+32); } return 0; }

//#include<iostream> #include<cstdio> //#include<algorithm> //#include<cmath> //#include<string.h> using namespace std; int main() { char n; scanf("%c",&n); if(n>='A'&&n<='Z') printf("%c",char(n-'A'+'a')); else printf("%c",char(n-'a'+'A')); return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ char a,b; cin>>a; b=int(a); if(b>=97&&b<=122){ b-=32; cout<<char(b); return 0; } if(b>=65&&b<=90){ b+=32; cout<<char(b); return 0; } }